1. Field of the Invention
The present invention relates generally to internal combustion engines, and particularly to a split-chamber rotary engine that combines mechanically independent rotary and reciprocating features, including a rotary power module with one or more reciprocating compressor modules.
2. Description of the Related Art
Innumerable different configurations of internal combustion engines and expansion motors have been developed in the past. The reciprocating piston internal combustion engine commonly known as the piston engine in its various forms (e.g., two-stroke and four-stroke spark, diesel ignition, etc.) has been accepted overwhelmingly as the engine configuration of choice for nearly all stationary and mobile applications. The refinement of the reciprocating piston engine since its inception has resulted in such engines developing smooth power and having great reliability, in most cases, as well as being simple to operate during normal use.
Nonetheless, the reciprocating piston internal combustion engine principle, by its nature, is not particularly efficient. The major problem is that this engine configuration combines the function of an air compressor for drawing in and compressing the intake charge and expelling the exhaust gases with the function of an expansion motor for using the power produced by the combustion of the air and fuel mixture in a single chamber. The air compression function is reasonably efficient, as the piston force and compression requirement are well matched with one another during the compression stroke.
However, the power stroke of the reciprocating piston engine is relatively inefficient. This is due to the basic design of the mechanism, which causes the expansive force of the heated combustible mixture to develop its greatest force at very nearly the top position of the piston, called top dead center. When the piston is at top dead center, the torque arm defined by the crankshaft throw is zero, and thus no torque is developed, regardless of the force developed upon the piston in the combustion chamber. As the crankshaft rotates, the torque arm increases from zero to a maximum at 90 degrees from top dead center. However, here the piston is at mid-stroke and the energy of the mixture is about half-spent. Also, friction between the sides of the piston and its piston rings and the cylinder wall is at its greatest at this point, due to the angular offset of the connecting rod. The overall result is an engine configuration that is not optimized for efficiency.
In response to the above considerations, other internal combustion engine configurations have been developed, the majority of these being of the rotary type. Among the rotary internal combustion engines the most successful is the Wankel engine. The classic Wankel configuration with two chamber lobes and a three-sided rotor develops relatively low torque at high rpm, requiring torque multiplication and speed reduction in the form of transmissions, gear reduction differentials, etc. While the modern reciprocating engine also develops its maximum torque at relatively high rpm in order to overcome some of the inefficiencies noted further above, the need for much higher rpm for the production of reasonable torque output is a negative characteristic of the Wankel type rotary engine.
A number of variations of rotary configuration internal combustion engines have been developed in the past, as noted further above. An example of such is found in Japanese Patent No. 63-285,224, published on Nov. 22, 1988. This reference describes (according to the drawings and English abstract) a rotary engine having a case with a cam-shaped rotor therein. The case includes radially sliding vanes therein for defining the internal operating volumes of the engine. Conventional poppet intake and exhaust valves are provided.
Japanese Patent No. 1-080,721, published on Mar. 27, 1989, describes (according to the drawings and English abstract) another rotary engine having cam-shaped rotors therein with radially sliding vanes extending through the peripheral wall of the stationary case.
Japanese Patent No. 2-049,927, published on Feb. 20, 1990, describes (according to the drawings and English abstract) another rotary engine having radially sliding vanes extending through the peripheral wall of the stationary case, with the inner tips of the vanes bearing against the periphery of the non-circular rotor within the case.
French Patent No. 2,643,945, published on Sep. 7, 1990, describes (according to the drawings and English abstract) a rotary engine with two laterally joined chambers, each having a rotor with radially extending vanes therein. One rotor and chamber acts as a compressor, with the compressed charge passing to the second rotor via a periodically opened passage timed to permit the flow from compressor to combustion chamber at the proper time.
German Patent No. 4,029,144, published on Mar. 12, 1992, describes (according to the drawings and English abstract) a rotary engine having a case with a circular internal volume and a smaller diameter rotor eccentrically installed therein. The rotor has a series of radially extending and retracting vanes to define a series of variable volume working chambers between the outer circumference of the rotor and the inner circumference of the case.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a rotary engine solving the aforementioned problems is desired.